Locking the Script

Imagine you've broken down the whole script, built a schedule, and told fifty crew members that the big fight is "Scene 42 on page 55." Then the writer adds a paragraph to page 10 — and now every page number after it shifts, and "Scene 42" isn't on page 55 anymore. Chaos. Call sheets are wrong, the schedule is wrong, everyone's confused. That's the problem locking the script solves. Before you break anything down, you freeze the script's numbering so it stays stable no matter what changes later. It's an unglamorous but absolutely essential step.

What "locking" means

A locked script is a version that's been declared the official production draft, with its page numbers and scene numbers fixed permanently. From the moment of lock, those numbers never change again, even when the script is revised. Locking does two things:

• Locks the scene numbers. Every scene gets a permanent number (Scene 1, Scene 2, Scene 3…). Once locked, Scene 42 is always Scene 42, forever. This is what the breakdown, schedule, and call sheets all reference.
• Locks the page numbers. Page 55 stays page 55. Everyone flipping to a page sees the same content, so references never drift.

Locking usually happens once the script is finished enough to go into prep — after the creative rewrites are essentially done. It's the formal handoff from "we're still writing this" to "we're making this."

Handling changes after the lock: A-pages and revisions

But scripts do keep changing during production — lines get cut, scenes get added. If the numbers are frozen, how do you insert new material? The industry has an elegant system that lets the script evolve without ever renumbering:

• A-pages (and A-scenes). Need to add a page between 55 and 56? It becomes page 55A. A new scene between 42 and 43 becomes Scene 42A. The surrounding numbers never move — you just insert lettered ones.
• Revision colors. Each round of changes is printed on a different colored paper in a standard order (white, then blue, pink, yellow, green, and so on). At a glance, anyone can see which pages are the newest revision.
• Revision marks. An asterisk in the margin flags exactly which lines changed on a revised page, so crew don't have to re-read the whole thing.

This is why you'll hear "shoot off the blue pages" or "that's on page 22A" on a set — it's the language of a locked script staying organized while it evolves.

Why it has to come first

Locking is step one of the breakdown for a simple reason: the breakdown records information against scene numbers. "Scene 42 needs a vintage car" is only useful if Scene 42 will always be Scene 42. If you broke down an unlocked script and the numbers later shifted, your entire breakdown — and everything built on it — would point to the wrong scenes. So: lock first, break down second. On a small production you may be doing both yourself, but the discipline is the same — freeze the numbering before you start itemizing.

With a locked script in hand, you can start measuring it — and the first measurement is scene length, counted in a peculiar but powerful unit the whole industry uses: eighths of a page. That's next.